how is the gravitational field strength of a graviational field defined?

the strength, g, is the force per unit mass on a small test mass placed inside the field

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How is a radial gravitational field represented?

Field lines all around going towards the centre of the object

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How is a uniform gravitational field represented?

Field lines all parallel, the stronger the field the denser the field lines (more in an area)

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Is the gravitational field attractive, repulsive or both?

Always attractive

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Is gravity a scalar quantity or vector?

Vector because its direction is towards the centre of the object which has the gravitational field

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What quantity is g?

Vector

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What type of fields do point masses have?

Radial

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What is gravitational potential, V at a point?

The gravitational potential energy that a unit mass at that point would have (1 kg mass, has 10J of potential energy at point Z then gravitational potential is 10Jkg^-1

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What is the equation for gravitational potential?

V = - GM/r

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How does the graviational potential change from the surface?

Negative and increasing with distance from the mass

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What does the gradient of a curve of V (gravitational potential) against r (radius) show?

Gravitational field strength

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What is the gravitational potential at an infinite distance?

zero

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What is gravitational potential difference?

Energy needed to move a unit mass

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What happens when you move an object in a graviational field?

It does work against gravity

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What does the energy needed to do work against gravity depend on?

Mass of the object and the potential you move it through

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What is the relationship of an objects gravitational potential energy at a given gravitational potential?

dEp (gravitational potential energy) =mdV (d is for delta)

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What keeps planets and satellites in orbit?

Gravitational forces

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What is a satellite?

A smaller mass which orbits a larger mass

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What is the equation for orbital speed?

v = (Gm/r)^1/2

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Does the total energy of a satellite change or stay constant?

Remain constant

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Does the kinetic and potential energy change or stay constant?

The satellites speed and distance above the mass remains the same so constant

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In an elliptical orbit, when does the speed increase and what effect is there to the kinetic/potential energy?

When the height decreases (speed decreases when height increases) therefore kinetic energy increases as height decreases and potential increases and height increases.

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What are geosynchronous satellites?

Orbit directly over the equator and are always above the same point on the Earth.

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What is the angular speed of a geosynchronous satellite?

The same as the Earth

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What is the orbit of a geosynchronous satellite?

One day

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What are geosynchronous satellites used for and why?

For sending TV and telephone signals because satellite is stationary relative to the Earth to a certain point on the Earth so you don’t need to alter angle of the receiver.

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How are equipotential lines represented near the surface of the Earth?

as horizontal lines (parallel to the ground) as gravitational field over a small region is uniform

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Other cards in this set

Card 2

Front

how is the gravitational field strength of a graviational field defined?

Back

the strength, g, is the force per unit mass on a small test mass placed inside the field

Card 3

Front

How is a radial gravitational field represented?

Back

Card 4

Front

How is a uniform gravitational field represented?

Back

Card 5

Front

Is the gravitational field attractive, repulsive or both?

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